Defect Image Classification Apparatus Using Switching Logs

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Solution Overview

Problem

In semiconductor manufacturing, the efficiency of manual defect classification (MDC) is hindered by the need for manual confirmation and modification of automatic defect classification (ADC) results, as ADC cannot completely classify a wide variety of defects, leading to inefficiencies in defect image classification.

Innovation Solution

A defect image classification apparatus that includes an image acquisition unit, automatic classification processing, manual classification processing, and a control unit to selectively display images from multiple detectors based on user input and switching logs, optimizing the initial display for defect kind specification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If ADC is used for defect classification, then classification speed is improved, but classification accuracy deteriorates for wide variety of defects

Engineering Contradiction:
Improveclassification speedVSAvoidclassification accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the classification workflow into two distinct phases: automatic classification (ADC) for initial high-speed processing, and manual classification (MDC) for accurate verification of ambiguous cases. This segmentation allows the system to leverage the speed of ADC while maintaining the accuracy of MDC through selective application.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial automation by using ADC only for the portion of defects that can be confidently classified, while reserving MDC for cases requiring higher accuracy. The system performs excessive classification actions (both ADC and MDC) on borderline cases to ensure accuracy, rather than relying solely on ADC.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If MDC is performed to improve classification accuracy, then classification accuracy is improved, but work efficiency deteriorates

Engineering Contradiction:
Improveclassification accuracyVSAvoidwork efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary classification using ADC before MDC. By pre-processing defect images through automatic classification, the system reduces the volume of images requiring manual review, thereby maintaining accuracy while improving overall work efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where MDC results are used to refine and improve ADC performance over time. This feedback loop allows the automatic classifier to learn from manual corrections, progressively improving accuracy while reducing the burden of manual work.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If multiple defect images are displayed for comparison in MDC, then defect specification accuracy is improved, but operation complexity increases

Engineering Contradiction:
Improvedefect specification accuracyVSAvoidoperation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and displays only the most relevant defect images for comparison, rather than showing all available images. By selectively extracting key images that provide the most diagnostic value, the system maintains specification accuracy while reducing operational complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system applies local quality by displaying different numbers of images depending on the specific defect type and classification context. For well-defined defects, fewer images are displayed, while for ambiguous cases, more images are shown to aid specification, optimizing the balance between accuracy and complexity.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Improves the efficiency of MDC by ensuring that the most suitable images for defect kind specification are displayed initially, reducing the need for manual switching and enhancing the accuracy and speed of defect classification.

Implementation Method 1

signals obtained by detecting secondary particles obtained by emitting charged particle beams to a sample by the plurality of detectors

Methodology Applied
Scientific EffectSecondary particle emission:

Data Source

PatentUS10074511B2Defect image classification apparatus
Publication Date: 2018.09.11 HITACHI HIGH TECH CORP
  • US10074511B2 patent drawing
  • US10074511B2 patent drawing
  • US10074511B2 patent drawing

AI summary

A defect image classification apparatus includes a control unit that selects images obtained from at least some detectors among a plurality of detectors, associated with kinds of defects to be a classification result of an automatic defect classification processing unit, as images displayed initially on a display unit. The control unit associates the kinds of the defects and the images displayed initially on the display unit, on the basis of a switching operation log when a user classifies images of defects determined previously as the same kinds as the kinds of the defects determined by the automatic defect classification processing unit.